1. Field of the Invention
The present invention relates to a process cartridge and an electrophotographic image forming apparatus to which such a process cartridge can removably be mounted.
The "electrophotographic image forming apparatus" is an apparatus for forming an image on a recording medium by utilizing an electrophotographic image forming system and may include, for example, an electrophotographic copying machine, an electrophotographic printer (such as a laser beam printer), an electrophotographic facsimile, an electrophotographic word processor and the like. The "process cartridge" may incorporate therein an electrophotographic photosensitive member and either or both of a charge means and a cleaning means as a cartridge unit which can removably be mounted to an image forming apparatus. By using the process cartridge, since the process cartridge can be mounted on and dismounted from the image forming apparatus by the user himself, the maintenance of the apparatus can be facilitated.
2. Related Background Art
In conventional electrophotographic image forming apparatuses using an electrophotographic image forming process, a process cartridge wherein an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally incorporated into a cartridge unit, which can removably be mounted to an image forming apparatus has been used. By using such a process cartridge, since the maintenance of the apparatus can be performed by the user himself without the help of an expert, the operability can be improved remarkably. Thus, the process cartridge has widely been used in electrophotographic image forming apparatuses.
In such a process cartridge, a driving force transmitting means is constituted by a gear train including a drum gear secured to an electrophotographic photosensitive member supported by a cartridge frame, a roller gear secured to a developing roller, a gear secured to a toner feed member and idler gears, which are meshed with each other. When the process cartridge is mounted to the image forming apparatus, the drum gear is engaged by a drive gear of the image forming apparatus, to thereby transmit a driving force of the drive gear to various elements in the process cartridge.